The invention pertains to a composition designed to be used for dyeing human hair. The composition which is in liquid form, is quite stable in that form. When applied to the hair on one's scalp, for example, the hair gradually darkens in terms of brownish tones.
I am aware that the obtention of bright yellow colors of keratinaceous materials has been disclosed in, e.g., U.S. Pat. No. 2,719,104, those colors being obtained through use of a water soluble salt of bismuth, namely bismuth nitrate. To achieve brown colors, according to this prior art, white wool yarn is dyed with mixtures of bismuth and nickel, the depth of brown color being controlled by varying proportions of water soluble bismuth salts which produces the bright yellow color, and water soluble nickel salts which produce a deep brown.